ABSTRACT
Chronic regional arterial hypotension in the hind limbs of rats was produced by narrowing of the abdominal aorta. 14-19 days later the femoral artery and its main branches were isolated and perfused in vitro with oxygenated Krebs' solution. It was shown that constrictor responses to transmural electrical stimulation decreased 14-30 days after the constriction of the aorta, however, 90 days after the operation the responses were identical to those in the control. Guanethidine (1.10(-5) mol/l) decreased significantly the responses to stimulation in all the cases, while phentolamine (3.5.10(-5) mol/l) inhibited completely those reactions. The constriction of femoral arteries in response to noradrenaline infusion was the same in control and hypotensive vessels.
Subject(s)
Femoral Artery/physiopathology , Hypotension/physiopathology , Animals , Chronic Disease , Electric Stimulation , Femoral Artery/drug effects , Femoral Artery/innervation , Guanethidine/pharmacology , Hypotension/etiology , Norepinephrine/pharmacology , Phentolamine/pharmacology , Rats , Sympathetic Nervous System/drug effectsABSTRACT
In control rats, the relative red cell volume, mirroring the number of the functioning capillaries, was substantially greater in the soleus than in the gastrocnemius muscle, while the rise of this parameter seen during contraction of both the muscles, provoked by stimulation of the sciatic nerve, amounted to 37 and 54%, respectively. Fourteen days and 3-4 months after abdominal aorta constriction by a metal spiral, that produced a 30-50% lowering of the blood pressure in the vessels of the animal's body posterior, contractions of the gastrocnemius muscle did not provoke any increase in the relative red cell volume, whereas contractions of the soleus muscle were accompanied by a marked elevation of the relative red cell volume. It is assumed that the mechanisms underlying the working hyperemia of the gastrocnemius and soleus muscles are different.
